In an injection molding apparatus, the molding conditions of each of a plurality of mold cavities must be as close as possible to predetermined ideal molding conditions in order to ensure that high quality molded parts are produced. Any significant variation in the temperature and/or pressure of one or more mold cavities may result in the production of sub-standard molded parts.
Pressure and/or temperature sensors are used in injection molding apparatus to determine molding conditions of each of a plurality of mold cavities. It is known to position a pressure and/or temperature sensor along a nozzle melt channel, a manifold melt channel, and/or within a mold cavity to measure a processing condition at that respective location of the injection molding apparatus. In a valve gated injection molding system, it is known to position a pressure measurement device upstream of a valve pin such that it will measure pressure when a rear end of the valve pin is in direct or indirect contact therewith when the valve pin is in a retracted position.